Hold music. It’s something we would all rather not hear, if only because it means we’re on hold.

While Congressional offices would probably prefer to not put callers, especially constituents, on hold at all, it is inevitable. And when those callers are on hold, the music they hear can influence their perception of the Member and the office.

On the House side, offices get two choices: silence or patriotic music. Senators have more options: silence, classical music, instrumental versions of popular songs, patriotic music and country songs. The office of Sen. Jeanne Shaheen (D-N.H.) plays jazz, while constituents waiting to talk to Sen. Mark Udall (D-Colo.) will hear patriotic music. The Coloradan switched from country music this spring.

Although the options are limited to two for House offices and five for Senate offices, the hold music each office chooses can make a difference when constituents call, according to James Kellaris, a professor of marketing at the University of Cincinnati who has studied the influence of music on consumers.

A lot of that depends on the constituent’s mood. “A constituent in a bad mood, calling to lodge a complaint will react differently to a given piece of music than a supporter calling to congratulate a member of Congress on a legislative victory,” Kellaris said in an email.

The tastes of a Member’s constituents should also be a factor when an office is deciding on hold music options.

“[I]n general it makes sense to match music to constituents’ tastes,” Kellaris said. “Hence Members representing conservative districts should play music that is conservative in character. American classical or patriotic music seem reasonable choices.”

By that reasoning, the office of Rep. Billy Long (R-Mo.) — who was recently rated as the most conservative member of the Missouri delegation by the American Conservative Union — made the right decision when choosing to play patriotic music to constituents who call.

When it comes to music with lyrics, such as the country music option that Udall’s office and others employ, Kellaris recommends staying away.

“There is a hazard in using music with lyrics or even instrumental versions of highly familiar songs with well-known lyrics,” he said, explaining that the familiarity can cause callers to feel like they have been on hold longer.

Ultimately, the best strategy for offices when choosing hold music depends on the reaction they want to illicit from the callers, according to Kellaris.

“If the goal is to shrink perceived time on hold, familiar music should be avoided. If the goal is to calm irate callers, relaxing music may help but risks inflating time perception,” he said. “Ironically, when the goal is to encourage callers to persist on hold, it is best to play slightly agitating music.”

Correction: July 25, 2012

An earlier version of the article misstated the type of music played by the office of Sen. Mark Udall. The office now plays patriotic music.